The present invention relates to an automatic paper feeder for supplying sheets stacked on a stacking table one at a time to sheet-fed presses, sheet folding machines or the like, and more particularly to an improvement in a mechanism for adjusting the attitude of a separation suction device in such an automatic paper feeder.
Machines for handling sheets of paper, such as sheet-fed printing machines or presses and sheet folding machines, include a paper feeder for drawing sheets of paper stacked on a stacking table one by one and feeding the sheets in the forward direction into the machine. Known such paper feeders comprise separation suction devices movable vertically for sucking one of the sheets at a time, transport suction devices movable forward for feeding the picked-up sheet, an air blower for shuffling several uppermost sheets, and a probing foot for separating the sucked sheet from a next lower sheet on the sheet stack. The separation suction devices have suction nozzles which are positionally adjusted in advance so as to be inclined with respect to the direction of feed and a direction transverse thereto, and are movable upwardly in a direction at an angle to the vertical direction, so that the separation suction devices can correct the orientation of the sheet and keep the latter taut while moving upwardly. Such adjustment, however, is time-consuming and must be carried out by a skillful operator, must be repeated before proper adjustment is achieved, and results in an undesirable downtime of the printing machine or the like. There has been proposed a device for adjusting the separation suction devices while the printing machine or the like is in operation. The proposed device, however, is large in size and complicated, fails to effect smooth paper feeding, is noisy in operation, composed of an increased number of parts, costly to build, and relatively unsafe for the operator.